Urban Overdose Hotspots: A 12-Month Prospective Study in Dublin Ambulance Services

Background: Opioid overdose is the primary cause of death among drug users globally. Personal and social determinants of overdose have been studied before, but the environmental factors lacked research attention. Area deprivation or presence of addiction clinics may contribute to overdose. Objectives: To examine the baseline incidence of all new opioid overdoses in an ambulance service, and their relationship with urban deprivation and presence of addiction services. Methods: A prospective chart review of pre-hospital advanced life support patients was performed on confirmed opioid overdose calls. Demographic, geographic, and clinical information, i.e. presentation, treatment, outcomes, was collected for each call. The Census data were used to calculate deprivation. Geographical information software mapped the urban deprivation and addiction services against the overdose locations. Results: There were 469 overdoses, 13 of which were fatal; most were male (80%), of a young age (32 years), with a high rate of repeated overdoses (26%), and common poly-drug use (9.6%). Majority occurred in daytime (275), on the streets (212). Overdoses were more likely in more affluent areas (r = .15, P < .05), and in a 1000 m radius of addiction services. Residential overdoses were in more deprived areas than street overdoses (mean difference 7.8, t(170) = 3.99, P < .001). Street overdoses were more common in the city centre than suburbs (χ2(1) = 33.04, P < 0.001). Conclusions:
the identified clusters of increased incidence – urban overdose hotspots - suggest a link between environment characteristics and overdoses. This highlights a need to establish overdose education and naloxone distribution in the overdose hotspots.